Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		$ 300,171		$ 300,171		$ 299,181
Mortgage Servicing Rights, Fair Value [Member]
Fees and Commissions, Mortgage Banking and Servicing	[1]	110	$ 107	221	$ 214
Principal Amount Outstanding of Loans Serviced For Third Parties		136,762		136,762		140,801
Unpaid Principal Balance of Outstanding Underlying MSRs Purchased					5,900
Principal Amount Sold on Loans Serviced for Third Parties				567	221
Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		143,021		143,021		146,208
Commercial Mortgage Servicing Rights [Member]
Fees and Commissions, Mortgage Banking and Servicing	[2]	6	7	12	14
Principal Amount Outstanding of Loans Serviced		37,897		37,897		34,539
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		6,732		6,732		6,399
Servicing Asset at Amortized Cost		66		66
Consumer Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		136,289		136,289		139,809
Pillar Financial [Member]
Fees and Commissions, Mortgage Banking and Servicing	[2]	6	$ 3	9	$ 6
Principal Amount Outstanding of Loans Serviced For Third Parties		$ 31,165		$ 31,165		$ 28,140

[1] Recognized in Mortgage-related income in the Consolidated Statements of Income.

[2] Recognized in Commercial real estate-related income in the Consolidated Statements of Income.